2027 Chevrolet Silverado HD Adds New Diesel and Steering

2027 Chevrolet Silverado HD Introduces Major Engineering Updates

The General Motors 2027 Chevrolet Silverado HD and GMC Sierra HD receive major powertrain, steering, braking, and drive-mode updates, with U.S. dealer arrivals beginning in late 2026. The heavy-duty pickups continue production at the Flint Assembly Plant and Oshawa Car Assembly. The most significant changes include GM's first all-new in-house-designed heavy-duty diesel engine, a segment-first rack-and-pinion Electric Power Steering system, and a new electronic brake-boost architecture. These upgrades are designed around the demands of heavy-duty truck operation while adding new technology to the Silverado HD and Sierra HD lineup.

New Duramax 8.3L Diesel Delivers 555 Horsepower

The new Duramax 8.3L Turbo-Diesel V8 is the centerpiece of the powertrain changes, producing 555 hp and 1,230 lb-ft of torque. GM describes these figures as best-in-class for the segment. The engine will be produced at the company's DMAX plant in Brookville, Ohio, following a $920 million expansion that increases the facility to 1.4 million square feet. The investment brings engine machining and assembly together under one roof, creating a dedicated manufacturing base for the new diesel powertrain.

Upgraded Gas V8 and Allison Transmission

The standard enhanced 6.6L gas V8 also receives an output increase, reaching 412 hp and 472 lb-ft of torque. The engine is assembled at GM's Tonawanda Engine Plant in New York. Both the gas and diesel engines are paired with the Allison 10-speed 10L1000 transmission, which uses advanced shift logic to keep each engine within an optimal operating range. The combination is intended to provide smoother acceleration and stronger grade performance across the heavy-duty pickup lineup, particularly during demanding towing and hauling conditions.

Electric Power Steering Replaces Hydraulic Assistance

For 2027, Chevrolet and GMC HD pickups move to an all-new rack-and-pinion Electric Power Steering system designed specifically for heavy-duty truck requirements. GM identifies the technology as a segment-first for heavy-duty trucks. The new architecture replaces the previous hydraulic-assisted steering arrangement with an electrically assisted system. The change represents a major revision to the trucks' steering hardware and is part of the broader engineering update for the 2027 model year, alongside the new engines, braking architecture, and revised drive-mode calibrations.

Electronic Brake Boost Adds New Stopping Technology

The HD trucks also adopt a segment-first electronic brake-boost system as part of the 2027 updates. The braking package includes larger brakes and four-piston front calipers, with the new architecture intended to provide more confident and consistent stopping performance. GM is combining the electronic brake system with the broader chassis and control-system changes introduced for the new model year. Together, these updates address braking performance and control while complementing the trucks' heavy-duty powertrain capabilities and towing-focused engineering.

Updated Tow, Haul and Off-Road Drive Modes

The 2027 HD pickups receive an enhanced drive-mode strategy that includes updated Tow/Haul and Off-Road calibrations. GM is also adding an available Terrain Mode with one-pedal off-road capability. These changes extend the electronic control systems beyond the powertrain and braking hardware, allowing the trucks' operating modes to be calibrated for different driving conditions. The revised strategy is particularly relevant to customers using the heavy-duty pickups for towing, hauling, and off-road applications, where predictable vehicle response and control can be important during demanding operation.

Manufacturing Investment Supports the New Diesel

The new Duramax diesel also brings a significant manufacturing commitment from GM. The $920 million expansion at the DMAX facility in Brookville, Ohio, creates a 1.4-million-square-foot plant where machining and engine assembly are brought together. This investment supports production of GM's first all-new in-house-designed heavy-duty diesel engine described in the 2027 truck update. The gas V8 continues to be assembled at the Tonawanda Engine Plant in New York, while the HD pickups themselves remain built at the Flint Assembly Plant and Oshawa Car Assembly.

Industry Impact & Outlook

GM's 2027 HD truck updates increase the importance of powertrain output, steering technology, braking control, and electronic vehicle systems within the heavy-duty pickup segment. The new 8.3L Duramax gives the lineup a substantially revised diesel powertrain, while Electric Power Steering and electronic brake boost introduce new architectures to heavy-duty trucks. The manufacturing expansion in Ohio also connects the product update to a major investment in domestic engine production. The next stage will be the late-2026 U.S. dealer launch, when the updated Silverado HD and Sierra HD enter the market with these engineering changes.

Frequently Asked Questions

What is new about the 2027 Chevrolet Silverado HD?
The 2027 Chevrolet Silverado HD introduces a new 8.3L Duramax diesel, Electric Power Steering, electronic brake boost, and revised drive modes for heavy-duty use. The new diesel produces 555 hp and 1,230 lb-ft of torque, while the 6.6L gas V8 increases to 412 hp and 472 lb-ft. Both engines use the Allison 10-speed 10L1000 transmission, while the trucks gain larger brakes, four-piston front calipers, updated Tow/Haul and Off-Road calibrations, and available Terrain Mode with one-pedal off-road capability.